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09/28/2017: SO/NOAO Joint Colloquium Series: Dan Kelson, Carnegie


Title: Gravity + Noise

Questions about the growth of galaxies and their halos are largely approached using numerical simulations today, for the simple fact that the nonlinear growth of structure is complex. In this talk I introduce a new approach based on the stochastic diffusion of galaxies in the space of SFR and stellar mass. By bringing in relatively simple mathematical tools used in hydrology, finance modeling, and physics, for modeling diffusion when stochastic events are bewilderingly correlated, we can make tremendous headway in uncovering aspects of statistical galaxy evolution that would otherwise remain obscured from our intuition. Our initial results, modeling epochs when the universe can sustain unabated fueling of star formation (z>2), yield a compelling richness and complexity. They also challenge the information content of current data sets, and provide novel perspectives on how to extract meaningful astrophysics from the evolution of cosmic galaxy ensembles. Modifications to our approach will be needed to match the evolution of galaxies past cosmic noon, but promise to continue challenging doctrines implied by earlier analytical approaches.